Training idler for conveyer belts



Jime 19, 1934.- s. D, RoBlNs 1,963,099*- TRAINING IDLER FOR CONVEYER BELTS Filed Jan. l1, 1935 www 17 Patented June 19, 1934 I V1,963,099 'raAiNi'NG mma Fon ooNvEYEa BELTS f Samuel Davis Robins, Hewlett, N. Y., assignor te Robins Conveying Belt Company, Passaic, N. J.,- a corporation of New Jersey f Application January 11, 193s, serial No. 651,061

4 claim. '(01. 19a-2oz) This invention relates to training troughlvllg idler units for belt conveyers wherein the frame on which the supporting idlers or rolls for the belt are mounted is pivoted about a vertical axis and is "provided with supplementary devices of various typesv whichv are arranged in proximity to the respective edges of the belt and are operative, by the contact therewith of one or the otherof such edges when the belt deviates from its normal path,

1 "to produce a frictional moment which effects the partial ,turning of the frame about its vertical axis, thus shifting the series of idlers in the direction of travel of the belt in a manner to return the belt to its normal path.

In belt training devices vheretofore described of the kind mentioned the supplementary devices with which the transversely shifted or displaced belt co-act. are of such character that the edges of the belt are subjected to destructive rubbing 2 pressureso combinationsof parts which, in a preferred form,

will be hereinafter described, the scope of the invention being expressed in the appended claims.

In the drawing- 1 Figure 1 is a front elevation, partly in section, of a training troughing idler unit embodying `my invention, the conveyer belt being shown in transverse section. I

Fig, v2l is aj plan of the improved idler unit.

Fig. 3 is a side` elevation of the same.

Fig. 4 is a transverse vertical section through one of the outer idlers, the belt, and the brake for said idler, as on the line 4-4 of Fig. 1.

Referring to the drawing, A designates a troughing idler unit, and B a conveyer belt supported thereon. This unit comprises a series of idlers, in the present instance three, viz.; a horizontal idler 5 and two upwardly and outwardly extending idlers 6 arranged to impart a trough formation to the travelling belt in the usual manner. f 'I'he idlers are loosely mounted for inglependent rotation on shafts 'l which are supported on a suitable frame comprising a base 8 and bearing brackets 9. 'I'he base is pivoted about a vertical axis on an underlying supporting structure 10, the pivot being located midway between the ends of the base and in the vertical axial plane oi the idlers, whereby the frame and its appurtenances are bodily moved about the axis of the base i by the drag of the belt on one or the other of the outer idlers to which a braking action may be applied when the belt deviates from its normal path, as hereinafter described. e l

In the present instance the pivot for the base comprises a vertical pin 11 which is ailixed to the cross-member 12 ofl a bracket 13 depending 'u from the base, and which pin is rotatably seated in a vertical bearing 1 4' in the supporting structure 10. The cross-member v12 and the supporting structure 10 have opposed bearing surfaces 15 and 16, respectively, between which is preferably interposed a washer 17, of leather or other suitable material, effective toA apply frictional resistance to the movement of the idler base about its axis.

Pivoted, as at 18, on the respective end brackets 9 carried by the base are brake actuating devices comprising bellcranks, whereof the lower arm 19o! each extends beneath the adjacent outer idler 6 and has a recessed portion, 20, for a brake shoe, 21, formed of wood or other suit-v able material with a concave active surface which normally lies4 in close relation to, but out of contact with, the under surface of the adjacent idler. The arm22 of each bellcrank terminates in a spindle 23 uponwhich is rotatably mounted a roll, 24, that is located at and extends above the outer end of the adjacent idler 6, so that in r the event of the lateral swerving of the travelling belt from its normal pathto the right or leftthe higher edge ot the belt makes rolling contactA with the opposing roll 24' and thereby immediately swings the roll and the. bell crank about the fulcrum of the latter in a manner to apply the brake shoe directly to the under surface of the adjacent idler.

The Weight of the belt on this idler when the brake is applied produces suiileient frictional contact to insure rotation of the idler at all times, the action of the brake vresulting not in slowing down such idler but in ensuring suilicient drag of the belt thereon to cause a turning of the idler frame about the'pivot 11 effective to swing the series of idlers intogtraining position, with the result that the edge of the belt breaks contact with the brake actuating roll, and thereby releases the brake, the instantthat the training efiect starts to move the belt back towards its proper central position. At this point the pivotal idler structure remains at rest in a trainingirposi tion and does not return through any belt action switch the vidler structure into too extreme training position with the result that the belt may 5 pass beyond its central position and into light rolling contact with the opposite brake actuating roll. This will have the eiect of lightly applying the opposite brake to the adjacent idler with a consequently small swing of the idler structure counter to the iirst swing. The result of this slight counter movement will break contact between the edge of the belt and the opposing brake actuating roll.

It is to be noted that in the cases indicated such successive opposite swing of the idler structure will be less than the `preceding movement until the idler structure comes to rest, and in this condition it will remain at the proper training angle so long as those effects which singly or cumulatively disturb the central running of the belt remain at the constant value. Should a change in these disturbances take place, the idler will again be adjusted to a new stable position oi central belt operation. The washer 16 brings friction into play as a damping force which eliminates see-sawing or hunting of the idler structure about the vertical axis.

Since by the foregoing described construction embodying my invention, either edge of the travelling belt, according to the direction of lat-e` eral displacement of the belt, makes free rolling contact with the periphery oi an adjacent roll on a freely turning bearing and utilizes the displacenient oi the roll itseli` and the spindle on which it is mounted as a means to move the brake shoe into prompt breaking action against the adjacent inclined idler, the undue wearing oi' the edge or edges of the belt resulting from the contact of the belt with the actuating devices heretofore employed in belt training constructions for troughing idlers, is obviated.

Since, also, the frictional resistance oi the pivot or the idler base il is augmented'as hereinbeiore described, the tinning moment about the pivot to edect the training oi' the laterally displaced belt is solely produced by the drag ci the belt on the idler d to which the braking action is applied, A

llt is to be noted that, since in the foregoing described construction embodying my invention the pivot pin or the idler base is in the plane of the aries of the idlers, the idler unit is symmetrical in all respects, andthereiore is suitable for use in connection with reversible belts as `yell as with those that run in one direction only. Furthermore, that since the brake shoes 2l are located beneath the respective idlers 6, and under the upper run of the conveyor belt, such shoes are efectually shielded frommaterials that may be spilled from the belt.

lt is to be understood tnat my invention is not limited to the precise construction herein dis closed, as the structural features may be modied in various respects within the principle of the invention and the scope of the appended claims.

I claiml. Ina training idler unit for conveyer belts, a series of troughing idlers, a frame on which said idlers are mounted for independent rotation, said frame pivotally mounted to turn about a vertical axis in the'plane of the axes of the idlers, and brake mechanisms for acting on the respective outer idlers, each of said mechanisms including a freely-rotatable belt-actuated roll independent oi the adjacent idler and located at one end thereof in the path oi' the adjacent edge oi-a laterally shifted belt supported on the idler unit.

2. In a training idler unit for conveyor belts, a series ci troughing idlers, a pivoted frame on which said idlers are mounted for independent rotation, and brake mechanisms for acting on the respective outer idlers, each of said mechanisms including a lever fulcrumed adjacent the outer idler, a brake member on one arm. of the lever in co-operative relation to the said outer idler and a freely rotatable roll mounted on the other arm of the lever at the outer end. of the said idler and in the path 'of the adjacent edge of a laterally shifted belt supported on the idler unit.

3. lin a training idler unit for conveyer belts, a series of troughing idlers, la pivoted frame on which said idlers are mounted for independent rotation, and brake mechanisms for acting on the respective outer idlers, each of said mechanisms including a bell crank fulcrumed adjacent the outer idler, the shorter arm oi the bell crank extending beneath the said idler, and the longer arm oi the bell oranlsl extending upwardly adjacent the outer end of said idler, a brake member on the shorter arm arranged in close spaced relation to the under surface of the said idler, and a. freely rotatable roll mounted on the upper end of the longer arm of the bell crank' in the path. ofthe adjacent edge oi a laterally shifted belt supported on theidler unit.

d. The combination with 'a series of idlers, and a pivoted frame on which said idlers are mounted for rotation independently of each other, of belt= actuated training means comprising a lever fulcrurned on the frame, a braise member on one arm oi the lever, and a freely rotatable roll on the other arm of the lever, the brake member located adiacent the surface of one of the outer idlers, and the roll located in proximity to the outer end ci the said idler and in the path oi a laterally shifted belt supported on the idlers.-

Slll/iUEL DAVIS ROBWS.

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